7 Ways Loneliness (And Connectedness) Affect Mental Health

Loneliness is finally starting to get at least some of the attention it deserves—we may not be as "on it" as other countries, like the U.K. with its Minister for Loneliness, but we’re getting there. Like the push to dissolve the stigma around mental health issues, there’s been a similar increase in people’s honesty about their social connection, or lack thereof. And it turns out that people are pretty lonely these days. The percentage of people saying they have few or no confidants has risen precipitously in recent years. So if you're feeling lonely, you're...well, not alone.

As the research shows just how important social connection is for our health and mental health, and how detrimental loneliness can be, the value of speaking out—and changing our habits—becomes all the more clear. Here are some of the ways in which loneliness hurts us and social connectivity helps us, psychologically and physiologically.

Loneliness is contagious

A fascinating study looked at how loneliness is present in communities, and found that it spreads through a contagious process in which people seemed to “catch” loneliness from one another. As people became lonelier, they moved to the edges of social networks, creating a kind of domino effect. For instance, when one person reported an increase of one day per week of loneliness, his or her close friends also reported an increase. As the authors write, “efforts to reduce loneliness in society may benefit by aggressively targeting the people in the periphery to help repair their social networks and to create a protective barrier against loneliness that can keep the whole network from unraveling.”

Other work has shown that people who become lonelier over time also begin to trust others less, which creates a vicious cycle of loneliness and social isolation. These types of studies suggest that social connection is precarious, and vulnerable to different forces, making it all the more important to do what we can to keep our networks together and oneself involved.

Loneliness may increase inflammation

A few years ago, a study reported that people who reported being lonelier had higher biomarkers of inflammation, increased activity of inflammatory genes, and reduced activity of anti-viral genes. They also had increased activity of the sympathetic nervous system, the part of the nervous system responsible to the fight-or-flight response to stress or threats. In particular, loneliness seems to affect the hypothalamic-pituitary-adrenal (HPA) axis, which governs the stress hormones’ roles in the stress response. Similar changes were seen in monkeys who were less social, suggesting that these connections, which the authors say may be causal, are similar across at least some social species.

The connection is intuitive, since as humans were evolving many thousands of years ago, the feeling of loneliness would signal something dire: that you were not with your group, and therefore literally at risk. A derivative of this phenomenon is going on today, except loneliness can often be prolonged or chronic, which could produce significant changes in the stress response, and mood, over the long-term.

Loneliness is deeply connected to depression

This is related to the stress connection, but depression also has a distinct relationship to loneliness. It’s kind of a chicken-or-egg situation: does loneliness lead to depression or depression lead to loneliness? It’s likely a little bit of both, with each one contributing to risk of the other. One of the symptoms of depression is social isolation; and if you’re lonely chronically, affect or mood may suffer. In fact, a study looking at this very question found that there’s a “reciprocal” relationship between the two, where over the years each one contributes to the other.

But more recent work has found that loneliness is a stronger predictor of mental health than mental health is a predictor of loneliness. All the more reason to make sure you have social connections, not just on social networks, and nurture those real-life relationships.

Loneliness affects cognition, maybe even dementia risk

Studies have also shown that loneliness has some even darker consequences, like how we think: it’s been linked to problems with attention, executive function, cognitive function, and is even the risk for Alzheimer’s disease. A study out just this week followed over 12,000 participants for 10 years, and found a significant link between loneliness and dementia risk—those who reported being loneliest had a 40% greater risk for dementia.

"We are not the first people to show that loneliness is associated with increased risk of dementia," said study author Angelina Sutin in a statement. "But this is by far the largest sample yet, with a long follow-up. And the population was more diverse."

Social connection is perhaps THE key factor in well-being

As much as loneliness can hurt us, social connection seems to not only undo these effects, but it can protect our health and mental health is many ways. Numerous studies have looked at the connection between social connection and well-being, and all find that the one predicts the other. One of the most famous, a Harvard study following people for some 80 years, found that people with stronger social connections were the healthiest and happiest. In fact, social connectivity over a lifetime was the key variable that predicted happiness and longevity.

Even on a day-to-day timescale, social interactions predict feelings of happiness and well-being—in one study, even “weak” social interactions, like those with classmates or casual acquaintances predicted happiness, which suggests that we might not need to have only “deep” interactions to reap the psychological benefits of social connection. Just casual conversations with neighbors or colleagues on a daily basis might do something similar.

Social support reduces psychological stress, boosts resilience

The other part of social connection is that it's not just about inflammation and stress hormones—it provides psychological comfort and increases resilience to stress and trauma. For people who have experienced serious adversity, stronger social ties predict better outcomes. And it seems that social connectedness can be fostered in simple ways, and in the shorter-term. In one study, people who did a type of mindfulness training designed to boost social connection and compassion had significantly reduced feelings of stress as well as reduced stress hormone levels—up to 50%—compared people who underwent other types of training. Other studies using intriguing and sometimes bizarre methods have also arrived, again and again, at the profound effect of social connection both on our perceived stress levels and well-being.

Relationships can create context for finding purpose and meaning

Finally, relationships are critical in a headier way—they provide context to understand the world and make sense of it in new ways. When we’re torn about a decision and can’t get to a solution, sometimes communicating the issue to another person can provide the insight we’re searching for. And coming together with the people in your community, planning events, or engaging in a shared activity like gardening can make you feel like you’re part of a group that has the same larger goals and values. And this can lessen the load of existential ennui that many may feel these days.

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Addressing the loneliness epidemic in meaningful ways isn't straightforward, and it will likely involve not just individual efforts but community and policy efforts. But we can all do little things—putting down the phone and rekindling real friendships, reaching out to neighbors, and calling up family are some simple ways to be a little more social and help those around us do the same.